The present invention relates to vehicle suspension systems and, more particularly, to solid axle front suspension systems. While solid axle front suspension systems are known generally in the art, the solid axle front suspension system of the present invention is directed at improving the known prior art systems in a variety of respects.
It is desirous, for example, to have a leaf spring front suspension system which does not frequently encounter leaf spring windup. Front axle leaf spring windup can contribute to start-up shudder with a driven front axle, shudder during vehicle braking, and front tire toe angle change during vehicle braking. Moreover, earlier front axle leaf spring assemblies can transfer harsh longitudinal loads to a region of the suspension system beneath the driver's foot location, which in turn may influence driver perceived vehicle suspension noise, vibration and harshness levels.
It is also desirous to have a solid front axle suspension system wherein the shock absorber arrangement provides the desired amount of damping in vehicle roll and axle pitch conditions. Further, it is also advantageous to avoid shock absorber arrangements having low shock absorber lever ratios, because low lever ratios can impose restrictions on how the shock absorbers can be tuned. Moreover, it is desirous to balance the shock absorber lever ratios from the left side of the vehicle to the right side of the vehicle to improve vehicle performance on undulating roads.
An improved solid front axle suspension system might also include a steering linkage assembly which does not result in front tire toe steer during vehicle braking or create an on-center steering deadband, as can be found in certain earlier suspension designs. In addition, certain earlier steering linkage assemblies do not completely balance the percent Ackerman realized between a full left steering wheel angle and a full right steering wheel angle. Moreover, the amount in which the steering linkage ratio may vary is often limited in earlier designs by the amount of clearance provided to the front of the front axle.
Finally, it is also desirous to have a suspension system which simultaneously provides a significant reduction in the front tire toe angle change during vehicle braking, a considerable improvement toe change in the ride mode of the front wheels, adequate roll understeer during vehicle cornering, and an appreciable reduction in the amount of lateral forces transmitted into the vehicle body.
It is therefore an object of the present invention to provide a vehicle front suspension system that provides the driver with basic steering and vehicle handling improvements.
It is also an object of the present invention to provide a vehicle suspension system that improves vehicle braking performance and perceived braking feel.
It is also an object of the present invention to provide a vehicle front suspension system that transfers longitudinal loads to a forward region on the vehicle frame.
It is also an object of the present invention to provide a vehicle front suspension system that helps facilitate passenger ingress into and egress from the vehicle.
It is also an object of the present invention to provide a vehicle front suspension system which improves suspension noise, vibration and harshness levels.
It is also an object of the present invention to provide a vehicle suspension system which reduces leaf spring windup.
It is also an object of the present invention to provide a vehicle suspension system which reduces loads in the vehicle body, frame, and suspension under vehicle braking, vehicle acceleration, and rough road driving conditions.
It is also an object of the present invention to provide a vehicle suspension system which helps to maintain the appropriate position of driven axles and driveshafts to ensure proper driveline angles.
It is also an object of the present invention to provide a vehicle front suspension system which reduces front tire toe angle change during vehicle braking.
It is also an object of the present invention to provide a vehicle suspension system which reduces start-up shudder during vehicle acceleration.
It is also an object of the present invention to provide a vehicle suspension system which provides adequate damping in vehicle roll conditions.
It is also an object of the present invention to provide a vehicle suspension system which provides adequate damping in axle pitch conditions.
It is also an object of the present invention to provide a vehicle front suspension system that increases shock absorber lever ratio.
It is also an object of the present invention to provide a vehicle front suspension system that balances the shock absorber lever ratio from the left side of the vehicle to the fight side of the vehicle.
It is also an object of the present invention to provide a vehicle front suspension system that allows the steering linkage ratio to vary independent from the amount of clearance space provided in front of the front axle.
It is also an object of the present invention to provide a vehicle front suspension system that balances the ackerman of the front tires from the left side of the vehicle to the fight side of the vehicle.
It is also an object of the present invention to provide a vehicle suspension system which reduces ridesteer and provides optimum toe change in the ride mode of the front wheels.
It is also an object of the present invention to provide a vehicle suspension system which provides optimum roll understeer during vehicle cornering.